During initiation of an industrial robot, it is necessary to connect the drives of the axles with the control device of the industrial robot, that is, assign the correct drives to the control device. The connection is typically established by wiring the components by means of signal lines. An industrial robot generally means a manipulating machine that is equipped for automatic manipulation of objects with suitable tools and that is programmable in a plurality of axes, in particular with regard to orientation, position, and process sequence. Industrial robots typically include a control device and a robot arm having a plurality of axles and, optionally, links that are moved by drives which are controlled by the control device. A link typically forms a mechanical connection between the joints of two axles.
A control device that controls an industrial robot having at least two drives, i.e., at least two signal inputs and outputs, in practice has the problem that the components of the drive of the control device must be correctly assigned, i.e., the wiring between the drive and control device must be correct.
A drive typically comprises at least one actuator and one motion sensor, which each must be connected to a signal output, i.e. with a signal input of the control device. When the control device sends control signals to the drive, the actuator causes the links of the industrial robot to move accordingly, which is detected by the motion sensor. The motion sensor then sends corresponding motion signals to the control device, whereby the control loop is closed.
The assignment of the drive to the control device, in particular, the wiring of the various components, is usually carried out manually at the installation site of the industrial robot. During wiring, two basic types of errors can occur, both on the actuator side as well as the sensor side. They are inversion of signal lines and interchanging of signal lines. In the case of inversion, the polarity of the signal lines is reversed such that the direction of action of the actuator reverses or the direction information of the motion signal is given inverted. Interchanging of the signal lines results in drives being connected to incorrect outputs or inputs of the control device, i.e., interchanging results in a motion and/or a control signal that is incorrectly assigned to the drive and thus in a control loop that is not closed or closed incorrectly. As a result, the control device is no longer able to cause the desired movements of the axles intended by the control program.
Before initiation, the assignment is verified and, if necessary, an incorrect assignment is resolved. For this purpose, a initiation engineer commonly uses suitable commands to have the robot execute individual movements in order to verify the assignment. The verifications of the movements are done visually. Subsequently, the wiring is adjusted or the control program is changed manually. These corrections are necessary, in particular because incorrectly assigned drives are potentially dangerous. For example, if an axle under the effect of gravity is held at standstill by an actuator via a closed loop (i.e., compensating for the effect of gravity) and there is an inversion of the actuator-side signal lines, the control may cause the algorithm, which compensates for the gravity, to accelerate the actuator in the direction of gravity.
In addition, initiation by a initiation engineer is time-consuming and error-prone.
The object of the present invention is to eliminate or reduce the disadvantages described above by an inventive method according to claim 1.